1. Field
Embodiments of the present inventive concepts relate to a method of manufacturing a semiconductor device.
2. Description of the Related Art
In the formation of semiconductor transistor devices, it is becoming more common for metal gates to be employed than polysilicon gates, in order to improve device characteristics. Metal gates are commonly fabricated using a replacement metal gate process. The replacement metal gate process includes forming a trench by removing a dummy gate pattern and then forming a metal gate by filling the trench with a metal material.
With the demands for ever-increased integration of such devices, and with the corresponding reduction in the design rule, the resulting width of the upper region of the trench used for forming the metal gate is also reduced. As a result, an overhang may be formed in the upper region of the trench in the process of filling the trench with metal, resulting in the formation of void regions within the formed metal gate. Such void regions can have an adverse impact on device characteristics.